U.S. Marine Corps Lance Cpl. Zachary Larsen, a combat graphic specialist with Headquarters and Support Battalion Marine Corps Installations Pacific-Marine Corps Base Camp Butler, attempts to escape a simulated attack during a water survival advanced (WSA) course Jan. 29, 2020, at Fairchild Pool on Kadena Air Base, Okinawa, Japan. WSA is the highest swim qualification Marines and sailors can receive before attending the instructor’s course